This proposal involves an upgrade of the Michael E. DeBakey VAMC (MEDVAMC) research magnetic resonance imaging (MRI) scanner from the 3 Tesla Siemens Trio platform, which was purchased in 2008, to the Siemens 3 Tesla Prisma platform, which received Food and Drug Administration (FDA) approval in 2013. The current MEDVAMC research Trio model has reached the limit of available upgrades to improve its research utility. However, rather than replacing the entire scanner, Siemens has enabled an upgrade process from Trio to the Prisma platform, whereby the core magnet is retained, but critical hardware and software that improve its functionality can be installed with relatively little downtime or costly and disruptive changes to building infrastructure. This cost-effective and efficient procedure allows continued use of the hardware elements that do not necessarily benefit from the upgrade and leverages the substantial investment already made by the hospital. The Prisma utilizes advances in increased gradient strength and improved parallel receive technology, which result in the capacity to acquire higher-resolution images at faster speeds. These advances are particularly important for pulse sequences used for diffusion imaging and functional MRI, both critical tools for neuroimaging research, and sequences commonly applied by MEDVAMC imaging researchers. Other advances in the Prisma include a full digital acquisition and direct radio frequency (RF) excitation to further improve image quality and advanced shimming solutions. Finally, the upgrade includes new pulse sequences that improve patient comfort through silent scanning and shorter scan times. In addition to the scanner itself, we request an accessory package for functional magnetic resonance imaging (fMRI) stimuli presentation that works in conjunction with the scanner. It would replace an existing Invivo Eloquence system that was acquired with our current Siemens Trio scanner and which is currently out of warranty and obsolete. The MEDVAMC team has a long-standing infrastructure to support the administration and maintenance of the requested equipment, including existing expertise in MR physics, radiology, and imaging analysis, as well as well-integrated access to Siemens scientists and research MRI technologists. Leadership responsibilities and the administrative structure forged during the MEDVAMC's Center of Excellence in TBI and extended as part of MEDVAMC's prominent role in the Chronic Effects of Neurotrauma Consortium (CENC) have led to successful maintenance and utilization of the research scanner for the last 8 years. The group of major users have been productive in imaging research specifically targeting Veteran populations, and the proposed scanner upgrade would further support and promote these research efforts. The Prisma scanner upgrade and the integrated SensaVue package would also facilitate development, testing and utilization of additional cutting-edge sequences designed by our group and others, such as the simultaneous multislice diffusion and fMRI sequences and correlated spectroscopy we are collaborating with others to optimize. Finally, the upgrade would promote wider interface and collaboration with other VA, academic and government institutions that are utilizing these newer scanners, such as is the case in the development of a normative imaging library. Utilization of this state-of-the-art platform at the MEDVAMC would facilitate creating and testing future standards in imaging acquisition and quality assurance and calibration that are rapidly developing, and support projects related to novel phantom development and standardized quality assurance as well as sequence development. The installation of this upgraded system would uniquely facilitate Veteran participation in additional innovative MRI research consortium and Merit Review projects in traumatic brain injury (TBI), post-traumatic stress disorder (PTSD), substance use disorders (SUD), and other medical and psychiatric conditions to enhance diagnosis, evaluate and monitor long-term change associated with these conditions, and evaluate potential treatment alternatives.